The goal was to document the gut microbiota ontogeny of a progeny of skin mucus-feeding discus fry during 100 days post-hatching. The V4 16S rRNA gene was sequenced to assess taxonomic structure of fry gut, parent mucus, and water samples. Our main results suggest that microbial symbionts both from the parents skin mucus and environmental water shape the structure of the fry gut microbiota.